The superior court entered a final judgment that is undisturbed by appeal. See generally Corey Outdoor Advertising, Inc. v. Bd. of Zoning Adjustments, 254 Ga. 221, 225–226(4), 327 S.E.2d 178 (1985) (“A permit issued for a use or structure which is forbidden by the ordinance is beyond the power of the officer to issue; consequently, it has no legal status, is invalid, and is itself entirely without power to clothe its holder with any legal rights thereunder. A permit for a use prohibited by a valid zoning ordinance, regulation, or restriction is void, of no effect, and subject to revocation.

The DOT presented no evidence that the County issued the business license by mistake or that the nature of Simmons' business was inherently illegal. Compare Corey Outdoor Advertising, Inc. v. Bd. of Zoning Adjustment c., 254 Ga. 221, 223 (3) ( 327 S.E.2d 178) (1985) (permit mistakenly issued not valid where billboard's placement violated city ordinance); see Plaza Liquor Store, 220 Ga. 618 (2); Troutman, 213 Ga. at 56. Simmons expended substantial time, effort and money on developing his property for his trucking business.

]" Id. at 76. Corey Outdoor Adv. v. Bd. of Zoning, 254 Ga. 221, 225(4) ( 327 S.E.2d 178) (1985); see 4 Rathkopf, The Law of Zoning and Planning, § 70:20 (2001). While we have acknowledged the existence of "constitutionally protected vested zoning rights" of a property owner under certain conditions, so as to preclude retroactive application of a zoning ordinance, id., the mere reliance on a particular variance without a showing of a substantial change in position by expenditures based upon an existing zoning ordinance does not vest rights in the landowner.

DekalbStone, Inc. v. County of DeKalb, Ga., 106 F.3d 956, 959 (11th Cir. 1997). Georgia law recognizes the concept of "grandfathering" nonconforming uses which predate new or amended zoning laws.Corey Outdoor Adver., Inc. v. Bd. of Zoning Adjustments, 254 Ga. 221, 327 S.E.2d 178, 184 (1985). Georgia law defines a protected nonconforming use "as a use which lawfully existed prior to the enactment of a zoning ordinance, or of an amendment to a theretofore existing zoning ordinance, and which therefore may be maintained after the effective date of the ordinance or amendment although it does not comply with the zoning restrictions applicable to the area."

"Nonconforming uses are uses of structures which were existing prior to the enactment of an ordinance rendering them nonconforming." Corey Outdoor Advertising v. Board of Zoning c. of Atlanta, 254 Ga. 221, 226 (4) ( 327 SE2d 178) (1985). "`A use which is merely contemplated for the future but unrealized as of the effective date of the regulation' does not constitute a nonconforming use. [Cit.

The act of issuing the permit was a ministerial function and the clerk who performed that ministerial function had neither the authority to waive any of the conditions of the zoning ordinance nor the authority to issue a curb cut permit which violated any of those conditions. Accord Corey Outdoor Advertising v. Bd. of Zoning, 254 Ga. 221, 224 ( 327 S.E.2d 178) (1985). "[E]quitable estoppel will not apply so as to frustrate or contravene a governmental function of a governmental unit."

The Supreme Court of Georgia has explained, "A permit for a use prohibited by a valid zoning ordinance, regulation, or restriction is void, of no effect, and subject to revocation." Corey Outdoor Adver., Inc. v. Bd. of Zoning Adjustments, 254 Ga. 221, 226, 327 S.E.2d 178 (1985) (citation omitted). In Corey, an outdoor advertising company was erroneously issued a permit to construct a sign that violated provisions of the city zoning ordinance.

Any pseudo-approval granted by the City's alleged delay in enforcing its ordinances was not - and could not be - legal, "and therefore there can be no estoppel."Corey Outdoor Advert., Inc. v. Bd. of Zoning Adjustments of City of Atlanta, 254 Ga. 221, 224 (1985) (quoting Flournoy v. Highlands Hotel Co., 170 Ga. 467, 471(1) (1930)). O.C.G.A. § 45-6-5.

4 Rathkopf, The Law of Zoning and Planning, § 72:1. See also Corey Outdoor Advertising v. Bd. of Zoning c. of City of Atlanta, 254 Ga. 221, 225 (4) ( 327 SE2d 178) (1985) ("Nonconforming uses are uses of structures which were existing prior to the enactment of an ordinance rendering them nonconforming."). Because the C-1 zoning did not permit use of the lot as a used-car lot, such usage was nonconforming; because the lot was legally used as a used-car lot prior to the 2002 zoning amendment changing the zoning to C-1, it was a pre-existing use.

. . . [E]quitable estoppel will not apply so as to frustrate or contravene a governmental function of a governmental unit." Corey Outdoor Advertising v. Bd. of Zoning Adjustments c. of Atlanta, 254 Ga. 221, 224 (3) ( 327 S.E.2d 178) (1985). Unofficial approval of CGP's plans without regard to the restrictions of the flood ordinances would frustrate Union County's duty to its residents to enforce the law and would violate the principle stated in Corey Outdoor Advertising.